From f7d0d3797fac6cad24ad9f86dd9baf65c586b434 Mon Sep 17 00:00:00 2001 From: Allison Henderson Date: Sun, 17 Jul 2011 23:17:02 -0400 Subject: [PATCH] ext4: punch hole optimizations: skip un-needed extent lookup This patch optimizes the punch hole operation by skipping the tree walking code that is used by truncate. Since punch hole is done through map blocks, the path to the extent is already known in this function, so we do not need to look it up again. Signed-off-by: Allison Henderson Signed-off-by: "Theodore Ts'o" --- fs/ext4/extents.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index f1c538e5055c..06b30b61205f 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3461,8 +3461,27 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, ext4_ext_mark_uninitialized(ex); - err = ext4_ext_remove_space(inode, map->m_lblk, - map->m_lblk + punched_out); + ext4_ext_invalidate_cache(inode); + + err = ext4_ext_rm_leaf(handle, inode, path, + map->m_lblk, map->m_lblk + punched_out); + + if (!err && path->p_hdr->eh_entries == 0) { + /* + * Punch hole freed all of this sub tree, + * so we need to correct eh_depth + */ + err = ext4_ext_get_access(handle, inode, path); + if (err == 0) { + ext_inode_hdr(inode)->eh_depth = 0; + ext_inode_hdr(inode)->eh_max = + cpu_to_le16(ext4_ext_space_root( + inode, 0)); + + err = ext4_ext_dirty( + handle, inode, path); + } + } goto out2; }